Abstract: There is disclosed an optical device for dispersion compensation of channels within a predetermined wavelength band, comprising: a waveguiding structure; and a grating structure formed in said waveguiding structure; characterized in that said grating structure has a Bragg frequency profile that is divided into contiguous periods, wherein the Bragg frequencies within each period vary between a lower Bragg frequency and an upper Bragg frequency, said lower and upper Bragg frequencies for each period both corresponding to wavelengths outside of said predetermined wavelength band.

Abstract: Improvements relating to thermally tunable fiber optical devices have been disclosed. In one aspect, a thermally tunable fiber Bragg grating device is provided with one or more heaters to (3a, 3b) produce a desired temperature profile along the grating, and one or more supporting auxiliary heaters (5a, 5b) are provided at the edges of the grating in order to compensate for temperature drops caused by heat loss to lower temperature surroundings. In another aspect, two heating structures are thermally connected to each other, such that dissipated heat from one of the structures supports the heating effect of the other structure.

Abstract: The present invention relates to an optical component, which comprises an optical fibre, which has a minimal functional arc radius in each point thereof, and which includes a thermally compensated portion, and a Bragg grating provided in a region of the thermally compensated portion. The optical fibre component comprises furthermore a temperature-compensating structure, which holds the thermally compensated portion of the optical fibre under tension in a linear direction for athermalizing the Bragg grating, and a housing for mechanical protection of the Bragg grating, which is provided with at least a first lead-through, and which housing has a maximal extension in the linear direction from a first housing end to a second housing end. The first lead-through has an exit end located outside the housing and an entrance end located inside the housing.

Abstract: A spectrally selective optical switch is disclosed. The switch comprises a first and a second optical waveguide each having a light guiding structure arranged to guide light along a predetermined path, the optical waveguides being arranged adjacent and parallel to each other; an external resonator defined by a first and a second mirror, said first and said second mirror being provided on opposite sides and outside of said first and second light guiding structures, and said external resonator being resonant to a specific wavelength; and a deflector provided in each of said first and second optical waveguide, the deflectors being arranged to deflect light propagating in one of the light guiding structures to the other light guiding structure by operation of said external resonator. A matrix switch is also disclosed.

Abstract: There is disclosed an optical device for dispersion compensation of channels within a predetermined wavelength band, comprising: a waveguiding structure; and a grating structure formed in said waveguiding structure; characterized in that said grating structure has a Bragg frequency profile that is divided into contiguous periods, wherein the Bragg frequencies within each period vary between a lower Bragg frequency and an upper Bragg frequency, said lower and upper Bragg frequencies for each period both corresponding to wavelengths outside of said predetermined wavelength band.

Abstract: The present invention relates to a device, method, array and use of the device for optical coupling. The device comprises first and second optical waveguides (13, 23) extending longitudinally with cores (14, 24) adapted to guide optical radiation (15), first resonator means, laterally surrounding the first waveguide, comprising first and second resonator members (18, 19), and second resonator means, laterally surrounding the second waveguide, comprising third and fourth resonator members (28, 29). The invention is characterized in that first and second deflector means (16, 26) are adapted to couple radiation propagating in the respectiv first and second waveguides with common radiation modes (30), which modes are defined by adjustable geometrical and material properties of the device, so as to obtain wavelength selective coupling of radiation guided by the first and second waveguides, provided the resonator means are tuned to the same resonance wavelength.

Abstract: The invention is a spectrally selective optical coupler with a new geometry and a new principle of action. An optical coupler according to the invention comprises an optical fiber and an external lightguide. In the fiber there is provided a deflector that is operative to deflect light of a predetermined wavelength into a propagating mode of said lightguide. The outcoupled light is transferred to a region remote from the outcoupling portion of the fiber. The invention can be used to couple light from a first to a second optical fiber.

Abstract: The present invention relates to a device, method, array and use of the device for optical coupling. The device comprises first and second optical waveguides (13, 23) extending longitudinally with cores (14, 24) adapted to guide optical radiation (15), first resonator means, laterally surrounding the first waveguide, comprising first and second resonator members (18, 19), and second resonator means, laterally surrounding the second waveguide, comprising third and fourth resonator members (28, 29). The invention is characterised in that first and second deflector means (16, 26) are adapted to couple radiation propagating in the respective first and second waveguides with common radiation modes (30), which modes are defined by adjustable geometrical and material properties of the device, so as to obtain wavelength selective coupling of radiation guided by the first and second waveguides, provided the resonator means are tuned to the same resonance wavelength.

Abstract: A spectrally selective optical coupler is disclosed, comprising a first and a second waveguide; an external resonator defined by at least a first and a second mirror; and a respective deflecting portion in each of said waveguides for coupling light between the waveguide and the external resonator. The waveguides are arranged between the mirrors adjacent to each other in a plane that is generally parallel to said mirrors; and the external resonator is designed such that a resonant mode within the external resonator overlaps the deflecting portion in the first and the second waveguide. The inventive coupler solves some limiting geometrical problems encountered in the prior art. A lateral extension of a mode in the external resonator overlapping both waveguides is obtained using a curved resonator mirror or refractive elements or portions within the resonator.

Abstract: The invention relates to methods and arrangements for channel balancing of a wavelength division multiplexed optical signal. Channel balancing according to the invention is performed by using a resonator that provides a selection region in which a selected channel has a substantially increased poser density relative to channels out of resonance. The selected channel is attenuated a desired amount, i.e. a desired amount of power is removed therefrom, by adjusting the properties of the selection region. In a preferred embodiment, attenuation is achieved by adjusting the selection region such that destructive interference is obtained for the selected channel in a fiber carrying tile multiplexed optical signal.

Abstract: A novel method and apparatus for fabrication of blazed and slanted fiber Bragg gratings is disclosed. The method comprises the step of simultaneously exposing the fiber with two mutually coherent light beams so as to create an interference pattern along a longitudinal axis of the fiber, wherein each one of said beams is brought into a line focus, which coincides with the core of the fiber. Further, the plane comprising the beams is rotated to provide a second angle relative to the fiber direction, said rotation giving rise to a blazing angle of the photo-induced grating elements.

Abstract: A spectrally selective optical switch is disclosed. The switch comprises a first and a second optical waveguide each having a light guiding structure arranged to guide light along a predetermined path, the optical waveguides parallel to each other; an external resonator defined by a first and a second mirror, said first and said second mirror being provided on opposite sides and outside of said first and second light guiding structures, and said external resonator being resonant to a specific wavelength; and a deflector provided in each of said first and second optical waveguide, the deflectors being arranged to deflect light propagating in one of the light guiding structures to the other light guiding structure by operation of said external resonator. A matrix switch is also disclosed.

Abstract: The invention relates to the coupling of light to and from an optical waveguide, such as an optical fiber. Light of a specific wavelength is deflected out from the fiber, or into the fiber, in a substantially transverse direction with respect to the propagation direction of light in the waveguide, by a deflector 16 arranged in the fiber core 10. Wavelength selectivity of the deflector 16 is provided by a Bragg grating means located in the fiber core 10. The deflected light is collimated, or converged towards a focus, by an interface 15 between a cladding 11, having one index of refraction, and an outer medium 12, having another index of refraction. The ratio between the radius of the cladding 11 and the radius of the core 10 made sufficiently small for the collimating, or converging, effect to appear.

Abstract: The invention is a spectrally selective optical coupler with a new geometry and a new principle of action. An optical coupler according to the invention comprises an optical fiber and an external lightguide. In the fiber there is provided a deflector that is operative to deflect light of a predetermined wavelength into a propagating mode of said lightguide. The outcoupled light is transferred to a region remote from the outcoupling portion of the fiber. The invention can be used to couple light from a first to a second optical fiber.